Rear projection screens have widely been utilized for video projection TV sets, micro film readers, computers and flight simulators.
From the descriptions in U.S. Pat. No. 4,573,764 and U.S. Pat. No. 4,418,986, and European application No. 0114395 rear-projection screens with vertical upright forerunning convex lenses on the front side in the screen's user position, and where between the convex lenses there are grooves, in which a material impenetrable to light is applied, are known.
In U.S. Pat. No. 4,573,764 the grooves between the lens tops are filled e.g. with coal dust particles, so that the tilted sides of the grooves are totally reflective to light beams from the projectors. The coal particles are then sealed with a lacquered film.
In U.S. Pat. No. 4,418,986 a total or partly reflecting surface is applied to the tilted side between the lens tape, upon which a material impenetrable to light is applied, e.g. black colour.
In the European application No. 0114395, the V-shaped groove between the two total reflecting sides is masked off with a body in a circular cross section, which has by and large the same diameter as the opening of the V-shaped groove or alternatively an inside back paper is applied to the total reflecting sides and filled with the black colour, where the above-mentioned body with the circular cross section is placed in the V-opening.
The principal difference between the present invention and the above-mentioned patents is that this invention does not have total reflecting sides or inside back paper applied to the sides of the grooves.